Rolling mill drive construction

ABSTRACT

A rolling mill drive construction including a tubular coupling box, a roll neck extending into one end of the coupling box and a spindle having a head extending into the coupling box from the other end. The spindle has an annular outwardly open groove disposed exteriorly of the coupling box and adjacent thereto. A circumferentially continuous retaining member is secured within the spindle groove for resisting movement of the coupling box along the spindle therebeyond. The spindle annular groove preferably has a diameter not less than the base diameter of the spindle. The retaining member may be a retaining ring having first and second ring elements pivotally secured to each other and a fastener element securing the retaining ring against relative separating rotation of the two elements. A second coupling box may be disposed in spaced relationship with the first coupling box and a second spindle head and pinion may be received within with a similar groove and retaining member securing the second box in place. The spindle heads have outwardly convex lateral portions in contact with the coupling box interior to permit efficient operation when the two coupling boxes are not axially aligned, thereby placing the spindle longitudinal axis in angular disposition with respect thereto. The radial outwardly disposed portions of the retaining member are preferably substantially continuous to provide uniform restraint against undesired coupling box movement during rotation of the spindle in such angular position.

United States Patent 1191 Bradel, Jr. et al.

.1111 3,826,108 1451 July 30, 1974 ROLLING MILL DRIVE CONSTRUCTION [76] Inventors: John H. Bradel, Jr., Markman Park Rd., R.D. No. 1, Baden, Pa. 15005; Lew Watkins, R.D. No. 2, Dundee, Ohio 44624 [22] Filed: Aug. 3, 1973 [2]] Appl. No.: 385,446

Primary ExaminerSamuel Scott Assistant Examiner-Randall Heald Attorney, Agent, or Firm-Arnold B. Silverman [57] ABSTRACT A rolling mill drive construction including a tubular coupling box, a roll neck extending into one end of the coupling box and a spindle having a head extending into the coupling box from the other end. The spindle has an annular outwardly open groove disposed exteriorly of the coupling box and adjacent thereto. A circumferentially continuous retaining member is secured within the spindle groove for resisting movement-of the coupling box along the spindle therebeyond. The spindle annular groove preferably has a diameter not less than the base diameter of the spindle. The retaining member may be a retaining ring having first and second ring elements pivotally secured to each other and a fastener element securing the retaining ring against relative separating rotation of the two elements. A second coupling box may be disposed in spaced relationship with the first coupling box and a second spindle head and pinion may be received within with a similar groove and retaining member securing the second box in place. The spindle heads have outwardly convex lateral portions in contact with the coupling box interior to permit efficient operation when the two coupling boxes are not axially aligned, thereby placing the spindle longitudinal axis in angular disposition with respect thereto. The radial outwardly disposed portions of the retaining member are preferably substantially continuous to provide uniform restraint against undesired coupling box movement during rotation of the spindle in such angular position.

17 Claims, 10 Drawing Figures 1 ROLLING MILL DRIVE CONSTRUCTION GENERAL BACKGROUND OF THE INVENTION This invention relates to rolling mill drive constructions and, more specifically, relates to a unique spindle design which is adapted to have a retaining member resisting undesired movement of a coupling box onto the spindle.

In rolling mills employed to reduce the thickness of steel, aluminum and other metals it is conventional to provide a coupling arrangement wherein a first coupling box receives a roll neck and an end of a spindle and a second coupling box receives a pinion shaft and the other end of a spindle. As the roll positions in the rolling mill are varied from time to time, the coupling boxes and spindle must be adapted to transmit rotary forces from the pinion shaft to the roll necks at various spindle angles. Arrangements of this sort which are sometimes referred to as Warbler couplings are shown in U.S. Pat. Nos. 1,047,133, 1,206,636, 1,261,548, 1,907,833 and 2,430,683.

One of the problems encountered with rolling mill spindle couplings is that the coupling boxes have a tendency to travel down the spindle, thereby creating a number of problems. First of all, the desired full contact between the fluted coupling box interior and the roll neck is lost. This results in uneven roll neck wear and may result in damage to the expensive rolls. In addition, vibration and noise problems are increased as a result of such movement. Also, the efficiency of transmission of the pinion shaft output to the roll necks is impaired. These problems are particularly acute with respect to coupling boxes which are not axially aligned as the spindle must operate while its axis is angularly disposed with respect to the coupling box axis.

U.S. Pat. No. 2,430,683 discloses a system for resisting undesired coupling box migration wherein one or more holes is drilled in the coupling box wall and an aligned groove in the roll neck is provided. Among the disadvantages of such an approach are the need to machine a groove in the roll neck, the need to provide openings in the coupling box and the weakening effect which these openings and grooves have on the respective members, as well as the cost of providing such openings and grooves. Also, the down time required for changing of spindles or coupling boxes may be increased. Finally, the violent mechanical rotational forces applied to the transmission assembly may result in loosening of the fastener and ultimate undesired migration of the coupling box.

It has been suggested to drill a hole in the spindle and introduce a pin through such that the pin will serve to resist undesired coupling box migration. One difficulty with such an arrangement is the fact that such an opening through the spindle tends to reduce spindle strength. Also, the pin would tend to provide only local restraint at the projecting sectors and not circumferentially continuous restraint, thereby permitting the coupling box to slide back and forth excessively on the roll or pinion necks for each 180 of rotation. This undesired longitudinal relative sliding movement would increase the wear on the coupling box and spindle wabbles. Another suggested circumferentially discontinuous restraining member totally unsuited to modern use with axially unaligned coupling boxes involves the use of a unitary resilient clip member which would cover only a portion of the spindle circumference in a reduced region and would lack essential uniform restraint characteristics in addition to providing difficulty in installation and removal as a result of the need to overcome the substantial inherent resiliency of the clip.

In commercial practices, one of the commonly employed means for resisting undesired coupling box migration has been the use of a fluted spindle which is provided with a series of hardwood planks in the flutes, with the planks being restrained in place by means of wires, springs, straps or the like wrapped around the same. Not only have such systems been burdensome as the wires, springs, straps and planks fracture under the compressive load imposed when the coupling boxes are nonaligned and require shutting down of the rolling mills to replace the same, but a substantial safety hazard is involved in view of the risk of the hardwood planks and/or wires, springs and straps becoming airborne without warning. In view of federal legislation in the area of occupational safety and increased attention, in general, to the matter of industrial safety, such risks are undesirable features of this approach. Another disadvantage of this common practice is the need to fabricate the hardwood planks, store them in sufficient quantities and to require shutting down of the mill for meaningful periods of time during replacement.

There remains, therefore, the need for an effective means for resisting undesired-coupling box migration in an efficient, safe manner without impairing spindle strength, without requiring expensive machining and manufacturing practices, and with a system susceptible of rapid installation to provide circumferentially uniform effective restraint even when coupling boxes are in axially nonaligned position.

SUMMARY OF THE INVENTION The above described needs have been met by the present invention which provides a circumferential groove in the spindle disposed exteriorly of the coupling box, but closely adjacent thereto. An annular restraining member which has a greater diameter than the coupling box minimum internal bore is secured within the groove in order to provide means for resisting migration of the coupling box onto the spindle. The retaining member is preferably in the form of a twopiece member having the component elements mounted for relative rotational movement and having fastener means for securing the same within the spindle groove.

It will generally be preferred to provide such a spindle having a central body portion, a pair of heads having outwardly convex lateral surfaces for extending into the two nonaligned coupling boxes and a groove interposed between each head and the central portion of the spindle.

It is an object of this invention to provide a rolling mill drive construction wherein spindle grooves are provided exteriorly of but adjacent to coupling boxes and circumferentially continuous retaining members which may readily and rapidly be secured within the grooves are so disposed as to uniformly resist undesired coupling box migration even when the spindle axis is angularly disposed with respect to the coupling box axes.

It is a further object of this invention to provide such a rolling mill drive construction wherein ease of instal- .a system wherein effective coupling box retention is establishd without undesired reduction of spindle strength.

It is yet another object of this invention to provide such a system which insures full efficient contact among the various transmission elements and even wearing of the roll neck.

It is yet another object of this invention to provide such a system wherein noise and vibration emanating from operation of the transmission is maintained at a reasonable level.

These and other objects of the invention will be more fully understood from the following description of the invention, on reference to the illustrations appended hereto.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 6 is a top plan view of a form of coupling box.-

FIG. 7 is an end elevational view of the coupling box shown in FIG. 6. g

FIG. 8 illustrates a front elevational view of an assembled retaining ring of the present invention.

FIG. 9 is a right side elevation of the retaining ring of FIG. 8.

FIG. 10 is a left side elevation of the retaining ring of FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now more specifically to FIG. 1, there is shown a coupling box 2 which has a roll neck 4 received within one end thereof. A spindle 6 has a generally cylindrical central portion 8, a pair of fluted heads l0, l2 and a pair of grooves 18, interposed between heads 10, 12, respectively, and central portion 8. Head 10 is received within one end of coupling box 2. The roll neck 4 and head 10 are longitudinally fluted and in keyed interlocking relationship with coupling box 2 which is also longitudinally fluted internally in a conventional fashion. Asa result, rotation of spindle 6 will produce coordinated responsive rotation of roll neck 4. The heads l0, 12 have outwardly convex lateral surfaces permitting efficient spindle operation at a wide range of angular positions with respect to nonaligned coupling boxes.

FIG. 1 also shows a second coupling box 30 which has a pinion neck 32 extending into one end of the same and head 12 extending into the other end. Pinion neck 32 and spindle head 12 are longitudinally fluted and cooperate with coupling box 30 which is internally fluted to provide coordinated rotational movement between the pinion shaft 32 and the spindle 6. It will be appreciated, therefore, that rotation of pinion shaft 32 responsive to a suitable power source (not shown) being energized produces coordinated rotation of spindle 6 which in turn drives roll neck 4.

Referring now to FIG. 2, the spindle grooves 18, 20 will be considered in greater detaiLGroove 20 is defined by a generally cylindrical circumferential portion 34 of the spindle 6 which cooperates with a first spindle defining surface 36 and a second spindle defining surface 38. As a result of cooperation of circumferential portion 34 and generally perpendicular annular first and second spindle defining surfaces 36, 38, a circumferentially continuous groove which is outwardly open is established. In order to avoid undesired weakening of the spindle 6, the spindle 6 preferably has a diameter at groove 20 taken across circumferential portion 34 which is not less than the average diameter of central portion 8. -(In the context of fluted central portion and the fluted groove circumferential portion shown in FIG. 3 and described below, the groove base diameter is preferably less than the spindle central portion 50 base diameter.) The groove depth is sufficient to resist unde'siredlongitudinal displacement of the retaining member along the spindle in an axial direction, while not being sufficient to impair spindle strength meaningfully.

Referring to FIGS. 1 and 2, it is seen that with the spindle heads 10, 12 inserted within the respective coupling boxes 2, 30, the grooves 18, 20 will be disposed exteriorly of the coupling boxes 2, 30 but in close adjacency thereto. In FIG. 1 there is shown a retaining member 40 secured within groove 18 by means of coil springs 42, 44. (If desired, a single spring or more than two springs might be employed.) It is noted that the retaining member 40 has an outer diameter greater than the minimum internal bore of coupling box 2. In a preferred embodiment of the invention, the outer diameter of retaining member 40 is of a size more near the outer diameter of coupling box 2 than to the minimum internal bore of coupling box 2. The preferred outer diameter of retaining member 40 is substantially equal to the outer diameter of coupling box 2. As a result, any tendency for the coupling box to move along the spindle toward central portion 8 will result in annular surface 46 of the coupling box 2 coming into contact with retaining member 40 which will resist further longitudinal movement of the coupling box along the spindle. Migration of the coupling box 2 along the roll neck 4 is prevented as a result of the shoulder 24 on the roll neck contacting surface 26 on the coupling box 2 and resisting movement in that direction.

Referring once again to FIG. 1 it is noted that coupling boxes 2, 30 are disposed in relative axial nonaligned positions, but that same clearance remains between surface 46 of coupling box 2 and retaining member 40. It is preferred that the portion of the retaining member 40 closest to the coupling box 2 be disposed in spaced relationship with respect to surface 46 so that clearance is provided to permit the desired spindle rotation when the coupling boxes 2, 30 are operatedin unaligned position. It is also preferred that retaining member 40 be circumferentially continuous and have a circumferentially substantially continuous radially outer portion in order to provide uniform restraint of the coupling box 2 as the spindle 6 rotates about its axis in its angular orientation between the unaligned coupling boxes.

Referring now to FIG. 3, there is shown a detail of a form of spindle of the present invention. In this embodiment of the invention the spindle has a central portion 50 which is longitudinally fluted, a pair of spindle heads 52, 54 and a pair of spindle grooves 56, 58. In the preferred form of the invention the spindle grooves 56, 58 will be disposed must closer to the spindle ends than to the center of the spindle. The spindle is preferably generally symmetrical about a plane taken through the transverse center thereof, with distance A equal to distance D and distance B equal to distance C. While in some spindles a generally centrally disposed annular recess is provided to establish a weak point for spindle fracture in the event excessive torque is applied to the spindle, an annular recess of this type placed within the spindle central region shall not be deemed to remove the structure from the expression generally symmetrical as used herein.

FIG. 4 shows a section of the spindle head 52 which is provided with outwardly convex lateral surfaces on a series of radial ribs 60 and an interposed series of flutes 62. Similarly, the fluted central spindle portion 50, as shown in FIG. 5, has a series of ribs 64 disposed in alternating relationship with a series of flutes 66. The circumferential groove defining surfaces 68, 70 may also be longitudinally fluted so as to provide for keyed interlock with the retaining member or, alternatively, may be circular. It is for some installations preferred that the fluted construction be provided so that keyed rotation of the retaining member and the spindle may be effected. It will be appreciated, however, that as the retaining member is secured within the grooves and longitudinal displacement of the same along the axis is thereby resisted, complementary circular configurations may be provided if desired, so long as the retaining member is circumferentially continuous.

Referring once again to FIGS. 4 and 5, it will frequently be convenient herein to make reference to the diameter or base diameter of fluted portions of the spindle. For convenience of reference herein the use of the term diameter shall refer to the maximum distance between outer surfaces. of a pair of opposed ribs 60, 64 such as the dimension E shown in FIGS. 4 and 5, respectively. Where the reference is to base diameter, the reference shall be to a diameter equal to the diameter of a circle defined by the inner extremities of a pair of opposed flutes 62, 66 such as base diameter F shown in FIGS. 4 and 5, respectively. It will be appreciated that for figures geometrically proportioned in section in such fashion that these definitions may not be literally applied, the reference to diameter is employed to refer to the maximum outer transverse dimension ignoring the presence of flutes and the reference to base diameter refers to the maximum diameter of completely solid section. For spindle sections which are cylindrical, the diameter will equal the base diameter and the terms will be employed interchangeably.

While for simplicity of description herein reference will be made to elements having circumferential continuity," the reference will be to a structure being continuous throughout a 360 degree periphery regardless of whether the portion has a round or circular shape, a fluted shape or other suitable configuration. The terms diameter" and annular will also be employed in this generic sense and are not limited to generally circular or round structures.

Referring now more specifically to FIGS. 6 and 7, there is shown a type of conventional generally tubular coupling box having an internally fluted configuration which is generally complementary with respect to the fluted configuration of the spindle heads which it will receive. It is noted that a plurality of flutes are generally complementary to ribs 60 shown in FIG. 4. Similarly, the inwardly directed radial ribs 82 are adapted to be received within flutes 62 shown in FIG. 4. The coupling box has a generally cylindrical exterior surface 84 which is provided with a number of core holes 86.

Referring now to FIGS. 8 through 10, a preferred form of retaining member will now be considered. With reference to FIG. 8, it is seen that the retaining member has a generally circular circumferentially substantially continuous outer periphery 92 and a fluted inner surface 94 which is of generally complementary relationship with respect to the outer surface 96 of the spindle 98 at the groove. The retaining member 90 in this form is a retaining ring which consists of first curved generally channel shaped element 100 and a second curved generally channel shaped element 102 which are pivotally connected as by a pin 104 passing through both members. (While for clarity of illustration the pin 104 has been shown with heads projecting beyond surfaces 112, 114, 116, 118 in FIGS. 9 and 10, it will generally be preferred to provide flush surfaces by countersinking and peening the pin heads so that they are flush with surfaces 112, 114, 116, 118.) The diametrically opposed portions of the two members are secured against relative outward rotation by means of a coil spring 106 which is anchored to pin 108 on first element 100 and is anchored to pin 110 on second element 102. It will be appreciated that the retaining member 90 may readily be secured to a spindle which has already been positioned within the coupling boxes without the need for requiring awkward end to end sliding. Also, installation may be effected by a single individual rapidly by merely opening the retaining member 90, allowing the members 100, 102 to pivot about pin 104 and establish relative closing movement about the spindle 98 within the groove sector. The member 90 is fastened in this position by securing the coil spring 106 to pin 110 and installation is thus completed. The coil spring will serve to resist relative outward rotational movement of the elements 100, 102. Also, should it become desirable to remove the spindle the spring 106 may be loosened and the retaining member readily removed. As is shown in FIG. 9, the manner in which the two ring sectors are secured by pivot pin 104 is readily apparent. If desired, other suitable forms of establishing joinder of the two members while permitting relative rotational movement, as by a hinge, may be employed. Similarly, should it be desired to effect attachment of the opposed ends by other means, a hand operated lever or a system such as disclosed in US. Pat. No. 709,366 might be employed. Additionally, for some installations where ready removal is not required, suitable fastener means may be employed in order to provide permanent or semi-permanent securement of the retaining member.

As is shown in FIGS. 9 and 10, the retaining member elements are adapted to fit together to provide a pair of substantially continuous curved surfaces 112, 114, 116, 118 on each element 100, 102 so that effective continuous circumferential resistance to undesired coupling box migration is provided. These surfaces 112, 114, 116, 118 provide a retaining member of uniform outer dimension which facilitates uniform restraint regardless of angular spindle position throughout axial rotation thereof.

While if desired other suitable retaining members may be provided, it will be appreciated that the present construction permits the maintenance employee to carry but a single element and suitable fastening means and either demountably or permanently secure the retaining member in position. If desired, although not preferred, a retaining member having a circumferentially continuous radially inwardly disposed portion disposed within the spindle groove and a circumferentially discontinuous radially outwardly disposed portion, with the latter provided by gaps, radial slots or notches, for example, may be provided. In order to permit effective restraint against undesired coupling box movement when a pair of coupling boxes are in nonaligned position and the spindle is rotating while the spindle axis is angularly disposed with respect to the coupling box axes, the retaining member must be circumferentially continuous and preferably have a circumferentially continuousradially outwardly disposed portion. This results in uniform restraint regardless of spindle axis angularity or the particular rotational position .of the spindle about the spindle axis. As used herein, a reference to a retainer member or portions thereof being circumferentially continuous-shall encompass members formed from assembly oftwo or more components.

While the spindle, coupling boxes and retaining member may be made out of any suitable material having adequate strength, desired ease of manufacture and priced within an economical range, it will frequently be advantageous to employ steels (such as carbon steel) or a metal alloy sold under the trademark Markaloy by the Markaloy Manufacturing Company of Pittsburgh, Pa. In manufacturing the grooves within the spindle this may be readily accomplished by either casting the grooves or machining the same.

While for purposes of illustration the spindles shown in FIGS. 1 and 3 have been provided with a generally cylindrical central portion 8 and a longitudinally fluted central portion 50, respectively, it will be appreciated that other configurations which are structurally and functionally suitable may be employed.

While for simplicity of illustration, the spindle groove has been illustrated as having been formed, at least in part, by annular recesses in the spindle, it will be appreciated that, if desired, a groove may be defined between a pair of spaced outwardly projecting radially outwardly directed annular wall segments.

It will, therefore, be appreciated that the rolling mill drive construction of the present invention provides an effective economical means of eliminating undesired coupling box migration along the connecting spindle regardless of spindle angularity with respect to.nonaligned coupling boxes. This is accomplished without necessitating any significant changes in rolling mill construction or pinion construction. Also, improved safety, ease of installation and avoidance of undesired end to end sliding during installation is eliminated. The retaining member is so constructed as to permit nonaligned coupling box placement without interfering with operation of the transmission mechanism. All of this is accomplished without weakening the spindle construction. In addition, undesired uneven wearing of the roll neck or damage to the rolls are avoided.

Whereas particular embodiments of the invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details may be made without departing from the invention as defined in the appended claims.

We claim:

1. A rolling mill drive construction comprising a tubular coupling box,

a roll neck-extending intosaid coupling box from one end thereof,

a spindle having a head extending into said coupling box from the other end thereof,

said spindle having an annular outwardly open groove disposed-exteriorly of said coupling box and adjacent thereto, and

a circumferentially continuous retaining member secured within said spindle groove resisting movement of said coupling box along said spindle therebeyond.

2. The rolling mill drive construction of claim 1 including said spindle head having outwardly convex lateral surface portions, whereby effective operation of said drive construction may be obtained even when said spindle axis is angularly disposed with respect to the coupling box longitudinal axis.

3. The rolling mill drive construction of claim 2 including said annular groove defined by a circumferential portion of said spindle in cooperation with first and second longitudinally spaced annular groove defining surfaces, and

said first and second annular groove defining surfaces having a diameter not greater than the internal diameter of said coupling box. 4. The rolling mill drive construction of claim 2 including said retaining member being a retaining ring having first and second ring elements pivotally secured-to each other, and

fastener means disposed generally diametrically across from the pivot connection resisting relative outward rotation of one of said ring element with respect to the other.

5. The rolling mill drive construction of claim 4 including a pin connecting said first and second ring members at said pivot connection, and

said fastener means including a coil spring connecting said first and second ring members, whereby said retaining member will be positively secured against accidental removal from said spindle but intentional removal may be effected readily.

6. The rolling mill drive construction of claim 1 including a second coupling box disposed in spaced relationship with respect to said first coupling box, the other end of said spindle extending into one end of said second coupling box,

a pinion neck extending into the other end of said coupling box,

said spindle having a second said annular outwardly open groove disposed exteriorly of and adjacent to said second coupling box, and

V a second circumferentially continuous retaining member secured within said spindle second groove to resist movement of said second coupling box along said spindle therebeyond.

7. The rolling mill drive construction of claim 4 including at least one said retaining member having a circumferentially substantially continuous radially inwardly disposed portion defining an inner opening of generally complementary shape with respect to the base surface of said groove within which it is disposed. 8. The rolling mill drive construction of claim 6 including said spindle at said annular grooves having a base diameter not less than the average base diameter of the portion of said spindle disposed between said annular grooves. 9. The rolling mill drive construction of claim 6 including said first and second retaining members having the portion disposed closest to the respective adjacent said coupling box disposed in spaced relationship with respect to said coupling box when said coupling box and said spindle are disposed in generally coaxial relationship, whereby axial rotation of said spindle is permitted when said coupling boxes are in relative nonaligned relationship. 10. The rolling mill drive construction of claim 7 including said retaining member inner opening being in keyed relationship with said spindle at said groove, whereby said retaining member will rotate with said spindle. 11. The rolling mill drive construction of claim 7 including at least one said retaining member having a circumferentially substantially continuous outer periphery, whereby uniform restraint against undesired coupling box movement will be effected regardless of the axial orientation of said spindle.

12. The rolling mill drive construction of claim 11 including said retaining member outer periphery being substantially circular.

13. The rolling mill drive construction of claim 12including said retaining member having an outer diameter of a size closer to the outer diameter of said coupling box than to said minimum internal bore of said coupling box.

14. A rolling mill spindle comprising an elongated spindle body portion,

a pair of fluted spindle heads at opposite ends of said spindle,

said spindle heads having outwardly convex lateral surface portions, I

a retaining member annular receiving groove interposed between at least one said spindle head and said spindle body portion, and

said spindle grooves defined by a circumferential portion of said spindle and axially spaced first and second annular groove defining surfaces, whereby a circumferentially continuous retaining member may be received within said grooves to resist movement of coupling boxes wherein said spindle heads are disposed along said spindles even when said spindle heads are disposed within coupling boxes which are not generally axially aligned.

15. The rolling mill spindle of claim 14 including the base diameter of said groove being not less than the average base diameter ofv said spindle body portion.

16. The rolling mill spindle of claim 15 including said first and second annular groove defining surfaces being disposed perpendicularly with respect to the base of said groove.

17. The rolling mill spindle of claim 15 including said spindle heads and said groove defining circumferential portion being fluted. 

1. A rolling mill drive construction comprising a tubular coupling box, a roll neck extending into said coupling box from one end thereof, a spindle having a head extending into said coupling box from the other end thereof, said spindle having an annular outwardly open groove disposed exteriorly of said coupling box and adjacent thereto, and a circumferentially continuous retaining member secured within said spindle groove resisting movement of said coupling box along said spindle therebeyond.
 2. The rolling mill drive construction of claim 1 including said spindle head having outwardly convex lateral surface portions, whereby effective operation of said drive construction may be obtained even when said spindle axis is angularly disposed with respect to the coupling box longitudinal axis.
 3. The rolling mill drive construction of claim 2 including said annular groove defined by a circumferential portion of said spindle in cooperation with first and second longitudinally spaced annular groove defining surfaces, and said first and second annular groove defining surfaces having a diameter not greater than the internal diameter of said coupling box.
 4. The rolling mill drive construction of claim 2 including said retaining member being a retaining ring having first and second ring elements pivotally secured to each other, and fastener means disposed generally diametrically across from the pivot connection resisting relative outward rotation of one of said ring element with respect to the other.
 5. The rolling mill driVe construction of claim 4 including a pin connecting said first and second ring members at said pivot connection, and said fastener means including a coil spring connecting said first and second ring members, whereby said retaining member will be positively secured against accidental removal from said spindle but intentional removal may be effected readily.
 6. The rolling mill drive construction of claim 1 including a second coupling box disposed in spaced relationship with respect to said first coupling box, the other end of said spindle extending into one end of said second coupling box, a pinion neck extending into the other end of said coupling box, said spindle having a second said annular outwardly open groove disposed exteriorly of and adjacent to said second coupling box, and a second circumferentially continuous retaining member secured within said spindle second groove to resist movement of said second coupling box along said spindle therebeyond.
 7. The rolling mill drive construction of claim 4 including at least one said retaining member having a circumferentially substantially continuous radially inwardly disposed portion defining an inner opening of generally complementary shape with respect to the base surface of said groove within which it is disposed.
 8. The rolling mill drive construction of claim 6 including said spindle at said annular grooves having a base diameter not less than the average base diameter of the portion of said spindle disposed between said annular grooves.
 9. The rolling mill drive construction of claim 6 including said first and second retaining members having the portion disposed closest to the respective adjacent said coupling box disposed in spaced relationship with respect to said coupling box when said coupling box and said spindle are disposed in generally coaxial relationship, whereby axial rotation of said spindle is permitted when said coupling boxes are in relative nonaligned relationship.
 10. The rolling mill drive construction of claim 7 including said retaining member inner opening being in keyed relationship with said spindle at said groove, whereby said retaining member will rotate with said spindle.
 11. The rolling mill drive construction of claim 7 including at least one said retaining member having a circumferentially substantially continuous outer periphery, whereby uniform restraint against undesired coupling box movement will be effected regardless of the axial orientation of said spindle.
 12. The rolling mill drive construction of claim 11 including said retaining member outer periphery being substantially circular.
 13. The rolling mill drive construction of claim 12 including said retaining member having an outer diameter of a size closer to the outer diameter of said coupling box than to said minimum internal bore of said coupling box.
 14. A rolling mill spindle comprising an elongated spindle body portion, a pair of fluted spindle heads at opposite ends of said spindle, said spindle heads having outwardly convex lateral surface portions, a retaining member annular receiving groove interposed between at least one said spindle head and said spindle body portion, and said spindle grooves defined by a circumferential portion of said spindle and axially spaced first and second annular groove defining surfaces, whereby a circumferentially continuous retaining member may be received within said grooves to resist movement of coupling boxes wherein said spindle heads are disposed along said spindles even when said spindle heads are disposed within coupling boxes which are not generally axially aligned.
 15. The rolling mill spindle of claim 14 including the base diameter of said groove being not less than the average base diameter of said spindle body portion.
 16. The rolling mill spindle of claim 15 including said first and second annular groove defining surfaces being disposed perpendicularly with respect to the base of said groove.
 17. The rolling mill spindle of claim 15 including said spindle heads and said groove defining circumferential portion being fluted. 